System of transmitting signal indications from railway signaling devices to vehiclesand for controlling same



Aug. 5, 1952 L. R. THOMAS l-rrAL SYSTEM oF TRANSMITTING SIGNAL INDICATIoNs FROM RAILWAY SIGNALING DEVICES TO VEHICLES AND FOR CONTROLLING SAME 2 SHEETS-Sl-IEET 1 Filed March 5, 1948 lj v kunt s QH, www

- INVENTORS Zzuffz j? fa/22a@ @Jffle Q. foac Allg- 5, 1952 L. R. THOMAS ETAL 2,606,281

SYSTEM OF TRANSMITTING SIGNAL INDICATIONS FROM RAILWAY SIGNALING DEVICES TO VEHICLES AND FOR CONTROLLING SAME r l l l 1 if; E Z gy?! 2 -fz/ 6PM/rami 160 -192 14%/ j-Jgg il ff 173 123 157 1551431 Q 1-/75a .fron

275, [250 l 'l l 77 22 IN V EN T ORSl Patented Aug. 5, 1952 SYSTEMv F TRANSMTTINGrv SIGNAL INDI- CATIONS FROM RAILWAY SIGNALING DE- VICES TO VEHICLES CONTROL- LING S'AME Lilburn R.. Thomas, Wilmette, and charles A. Crouch, Highland Park, Ill.

Application March 3, 194s', s'eriaiNo. 12,874

12 Claims. (Cl. 246-29) Our invention relates moreparticularly to a Ymethod of transmitting signal indications from railway signalling devices arranged along the right-of-way to receiving means and associated equipment on vehicles adapted to travel along said right-of-way, -such as railroad trains, trams and/or other suitable .vehicle for guiding the operator of the vehicle at preselected points.

One object of our invention is the provision of a method of utilizing space radio, for transmitting signal indications from the stationary railway signalling devices to the vehicles whereby the crew on a vehicle approaching said signalling devices will be given an indication of the nature of the signal.

A further object of our invention is the prov vision of a method of utilizing radio transmitting means-of any suitable character--for transmitting the signal indications from the stationary railway signalling devices to the vehicle whereby the brakes of the vehicle will be operated at predetermined periods during undesired or improper movement of the vehicle.

Another object of our invention is the provision of an additional safety device, .supplementing existing railway signalling devices, whereby it is impossible to pass the signalling devices without obtaining knowledge on the vehicle of the nature or indication of the signalling device.

A further object of the invention is the provision of a method whereby the crew on the approaching vehicle will be given a warning signal in the event the stationary signalling system fails to provide any signal to indicate that the signal system equipment is not functioning properly.

The aforementioned objects' and advantages of our invention, as well as other advantages inherent in the invention, will be readily comprehended from the detailed description Vof the accompanying drawings wherein:

Figure l is a diagrammatic illustration of a typical railway track with signalling devices at preselected fixed locations and involving means for transmitting signal indications to the crew of the approaching vehicle on the track.

Figure 2 is a diagrammatic villustration of the signal receiving means and associated equipment on the vehicle.

Figure l illustrates the equipment associated with one track circuit and the connecting circuits to interlock with the second track circuit. A indicates a vehicle or trainV approaching on the track in the direction of the arrow and provided with the receiving means generally indicated at B; the track consisting of thel insulated section C, insulated at D, D and E, E'; and insulated section F insulated at E, E and G, G.

The insulated track section C is shown provided with atrack relay I and battery 2; while insulated track section F is shown provided with track relay 3 and battery 4.

Assuming there are no trains in the trac sections C andF, in which'ca'se track relay I is held in the operated position by means of battery 2v and track relay 3 isheld in the 0perated position by means of battery 4. A conventional relay 5 is held in its operated position by means of a battery 6 through wire 1, contacts 8 and 9 of relay 3, wire I0 contacts II and I2 of relay I, wirey I3 to relay 5, through the coils of relay 5 and wire I4 to battery 6. A low frequency oscillator is I5 with associated battery 15a; band filters being shown at'I6, I1 and I8'. With relays I, 3 and 5 in their operated positions the signals from the low frequency oscillator I5 are transmitted to filters I6, I1 and I8 'by means ofwires I9, 28, 2|, 22, 23, 24, 25 and'26." Filters I6, I1 and I8 are adapted to pass three separate frequencies on to a modulator 21 with associated battery 21a as follows: The signal from filter I6 passes through wire 28, contacts 29 and 30 of relay I, wire 3| to modulator 21, returning to filter I6 on wire 32. The signal from filter I1 is transmitted by means of wire 33 to contacts 34 and 35 of relay 5, wire 36 to modulator 21, returning on wire 31 to filter I1. The signal from filter I8 is transmitted to modulator 21 by means of wires 38 `and 39. The signal from filter I8 is transmitted continuously. A high frequency oscillator 40 with associated battery 40a provides the transmitted carrier to modulator 21 by means of wires '4I and 42.

Modulator 21 is a conventional modulator and the modulated high frequency carrier coming from 'the master high frequency oscillator -48 hasthe three low frequency signals superimposed on it by meansof modulator 21 and the carrier is then transmitted to an amplifier 43 with associated battery 43a through wires 44 and 45 and from amplifier 43 to a directional locations along the track. rQperationfof the signal receiving equipment B arranged onthe vehicle 'ortrain `A-Figure 1, and as disclosed in Figure 2 Vwill mow beV described.

by antenna or suitable transmitting-element-53- consists of a high frequencyY carriergonly. "These transmitted signals will provide a green or clear indication on the train or vehicle A, later to be described.

If a train is in section F (insulated-atpoints E and E' and G and G') relay I will-be in its operated position by means of battery`2, while relay 3 Will be in its non-operated orfopen'position due to the train inrtrack section F shorting batteryr4 from the relay coils.

'AWhen ,relay 3 opensfits contacts 8 kand ,9, :bat

;tery.6fwillbe cutyfromrelay 5,-. causing contacts "34 and 55 to beropenedatnereby openingtheoutput of filter I1 and cutting that frequency out of the modulated signal. AUnder -this condition,

rthe high -frequency signaiw-rtransxnitted from ,-sourcer -will -haVe only ftwo frequencies super- 'I-8. V'I-he signal^from-fsource49'.wil1-=be trans-1 ;mitted continuously. i

These f transmitted: signals .fwill provide a7 yellow. or caution jindication r on u the train as 'well `4as -a yservice application `of 'ther brakes4 of the train as hereinafterdescribed fI-fatrain was intheiinsulatedsectionnC ofthe itracki (insulated at pointsD andD" and Ef-and .EW-'relay I f would-be in its non-operated ior open positionsgbecause batterygr2wouldbe shunted from vtherelay coils by the-train. Assuming thereis no train .in fsectioncF, :then relay' 3 Ywouldfbe -in itsroperatedgposition. "Withirelay I in its non- 'operated position, its contactsI-I and |2^and-29 land 3|).V would be operi;:and with `-contactsfll -and |52 .of relay ,I in open position, relay `5 `Would-be n.

opened which` in .turn would open its contacts 34 and 35, ewhichwould; openthe Aoutput, of. lter 1 `thereby eliminating lits .toutputf from the :signal transmitted by directional element "46. Con- .tacts229, and of relay being; openzwould elimi- :nate/the signal :from :filter 'J If6. ,signals :from signal source :43 would have merely The :transmitted theLlo'w frequency-signal io'f lfilter I8 `'superimposed on; it and L theztransmitte'd source-49 Ywould transmit 1a continuous signal as previously ex- .plained These signals: willprovidefagred' orstop :indication and .an emergency brake application as'hereinafterdescribed f Itishould be lnoted thatitransmitting elements .46 and 53 are 'directional'. and zare so'fpositioned that the receiving element on the traimproceedingin the direction of the arrow,in;Figurer1fwill pickgupathesignal before the train enters track section iC but notrafter enteringftraclfsection C. Direction transmitting elerr\.ents-45 'and S3-are also -so positionedthat-trains operating in,pre ceding or followingY track` sections v Vwill not ,pick up the signal indication.

The elements hereinbefore desc1ibed;andall disclosed in Figure 1r` constitute thesignal transmitting means'y `arranged .at'affixed location or ,The elements 'and The signal--or signals-transmitted by the transmitting means as disclosed in Figure 1 is received on an antenna or other suitable receiving element 56, arranged on the vehicle or train and passes over wires 51 and 58 to a high frequency "aniplifierliwith associatedfbattery 59a, thence through .wires i'L69 and-.GIzto .zaedemodulator 62 with associated battery 62a which separates the `low frequency components from the high frequency signals. The low frequency components `arezthen transmitted over wires 63 and 64 to an -amplier'i with vassociated battery 65a. The low frequencysignals pass from amplifier 65 over wires 65 and 61, to filter 12; wires 6G and 61, 10 and-1|,andr13rand 14 to filter 15; wires 66 and y61,:10 a`nd`1I, 68 and 69, and 16 and 11 to a filter `18, and vwires' and 61, 1D and 1|, |58 and 69 and 19 and 80 to a filter 8|. Filters 15, 18 and 8| pass the same frequencies as filters I6, I1 and I8 of the transmitting means in Figure 1, in nu- A-merical :sequence *.into .the following functions: i Theffrequency from-.filter 15 :passes over.: wires :82 and: 8'3 tozagrectier 184 from r'ectierlfl over wires w and 86' to at relay ,81. j The frequency andi 92 itc; a relay193. Theifrequency ,fromfllter 8| passes ov.e1" Wir es-9'4l and95 to .a rectifier '95 Vand, over swires? 91 and 93 :to a. relay 99.

`.fA 1local oscillator |00 with f associated .battery illla: sends a signalintcithaRF amplifier 59 Awith `associated".'battery `59a 'through wires IDI -and 4112. .This .signal :passes .through VvRF amplifier n59 over'wires .60 andfGI to demodulatorfz with associated battery 62a over ywires VIiI Vand'fli4'to -amp1ier165 overl wires $66 and 61j58 and'69, and 1D and "II: to lter112 :and fromflterl over wires |03 an`dII'0'4ftc la-rectifier |05, over wiresy |||6=and |||1 -toarelay |08, holding it normallyl operated Awith its contacts V4|09 and I|0 normally closed. fWith fcon'taets |99 ande-IIIJYclosed the circuit nfromvbatteryel through wire II2, through-lamp I I3, through wire I4 ltto contacts III] and |09 and-wire I5 stands closed, lighting 'thelamn In4 the event oscillator-|00, RFamplier 59, demodulator- 62,- amplifier 6 5, filter '1 2; rectifier |95, fail lto function properly, relay |08 -will 'become deenergized; therebyV opening itsA contacts I 09 and I I0. Battery III willthen extinguish lamp |13, showing that the circuit, is inoperative.

.On receipt of a.clear or kgreen signal from 'thetransmitting means,F i gure 1, consisting of .three 10W frequency signals as passed byfilters'l 6, YILanfdV I8 ofligurel .1, the signals are pckedup `by the antenna orsuitable receiving element v56, Figure 2, and passes through thecomponentsas previously described to operate relays 81, ,93 and 99. .Contacts |I 6.and |I1, II8 and I|9 ofrelay alareclosed; contacts |29 and.|2I,Y|-22 and|23 f`of. relay.81 are open;contacts |24 and |25 of relay 93 are closed; .contacts |28 andl21,V IZSand 129, Iancl 3|of,re1ay A93 are open; contacts .I32 and.|33, -|34 and |35, |36 and |31, |38 and 1390i relay ,99 are-closedland contacts |40 and 14|, |42 and-|43iofrelay 99 are open.

With relays r8-1, 93 vand 99 .in `their operated positions, energy `from battery |44 is applied throughwire- |45, contacts |32and `|33 of relay 99, Wire |46, contacts |24 and |25 ofrelay 93, wire |41, contacts IIB and-IH of relay 81, wires |48 and I-49,t o one winding of' relay |50. Due to VAcontacts-|26 and 5|.-2'1 of relay "93 being open, .battery |5| cannotzoperate relay |52.

As contacts |213 and |29 ofrelay-SS and contacts |20 "positions i position.

and |2| of `relay 81 are open, battery |53 cannot foperate relay'l54. y At the same time this signal is being' received, a Vsecond signal is being received on an antenna or other suitable receiving element |55 and transmitted through wires |56 and |51 to a high frequency amplifier |58 with associated battery |58a, thence through wires |59 and |60 to a rectifier |6| throughfwires |62 and |63 to a relay |64. This signal operates relay |64, closing contacts |65 and |66 ofv relay |64 and opens its contacts |61 and |68. With contacts l|65 and |66 of relay |64 closed, energy is applied from battery |69 through wire |10, contacts |65 and |65 of relayr |64, through wire |1| to contactA |40 of relay v99. With contacts |40 and |4| of relay 99 standing open, the relay |12 "cannot be closed. If a failure occurs and the signal is not received to operate relay |64, -the Venergy is'applied from battery |69 through wire |-through wire |13` through contacts `|61 and |68 of relay |64 through wire |14 through contacts- |39 and |38 of relay 99 which are closed through wire through wire |16fand |11 to one winding of relay |12, closing this'relay which locks up through its contacts |18 and |19 when relays 81,- 93 `and 99 vare in their non-operated ception of three tone signals whichr operated relays 81, 93 and 99, closing the contacts |60 and |8|. and |82 and |83 ofrelayrili.4

Relay |50, being a slow-release type, will stay closedk after the transmitted means have been passed which releases relays 81, 93 and 99 permits their respective contacts |22 and 23 of relay `81, `contacts 4|30 and |3| of relay 93, and contacts |42 and |43 of relay 99 toclose vand connects battery |84" to, the second winding of relay |50'through Wire |85, relay contacts |62, and |43,

Wire |86, relay contacts4 |38 and,|3|, wire |81, relaycontacts |22 and |23, wires |88, |89, |99 and |9| to the lsecond coil ofrelayv |59 through wire |92, contacts |870 and`|8| of relay |59,.Wire |93, |94, |95 and,|96backto battery |84. This locks relay |59 in its closed or operated position until the next transmitting means isl'passed .and i a new signal is received.

, Battery |91 operates green indication lamp |98 through wire |99, contacts |02 and |83 of lrelay |50 and wires 200 and 29|. As previously outlined', the green lamp |98 will remain operated untilV a'second signal is received operating relays 81, 93 and 99, opening their respective contacts |22 and |23, |30 and |3|,and |42 and y|43 releasing lock in circuit of relay |50 permitting it to 'return to an open or non-operative When .a 'signal is passed whose transmitting means is transmitting a yellow 'or caution indication consisting of low `frequency signals passed through lters vl5 and |8 of transmitting l means Figure 1, thesesignals are received as heretofore outlinedthrough lters 15 and 8 vrectiiiers 84and 96, operating relays 81.and 99. Relay 81 vin its operated 'position closes its con- Relay 50 has been closedV by the're- 9'3, wire 20L-contacts Maand Ils 'of reraym,`

and wires-205 and`206 to one winding of relay |52. Relays |50, |54 and |12 are in their non-operated or open position becauserelay 93 is non-operated, opening its contacts |24, andl25, removing battery |44 from relay |50; relay 81 is "operated,

'opening its contacts |20 and |'2|, removing battery |53 from relayv |54,"while relay |12 is nonoperated because relay |64 is operated, opening its contacts |61 and |68. Relay 99 is operated, opening its contacts |49 and |4|, and removing battery |69. i

Relay |52, being a slow-release'relay, is locked in the operated positionthrough its contacts 201 and 208 after transmitting means as outlined in Figure 1 has been passed. This 'locking is accomplished from battery |84 throughY wirefl5, contacts |42 and |43 of relay 99, wire |86, contacts |30 and |3| of relay 93', wire |81, contacts |22 and |23 of relay 81, wires |88,`|89l, |90 and 269 to relay |52, wire 2|0, contacts 201 and'208 of relay |52 and wires |94, |95 and |96. Contacts 2|| and 2|2 of relay |52 are closed thereby applying battery 2|3 through-wire 2|4 and contacts 2|| and 2|2 through wires 2|5 and 2|6 to a caution or yellow lamp 2 |1. The operation Aof relay |52 also closes its'contacts 2|9 and 2|9 which connect battery 220 through wires 22| and 222' through contactsn223 and 224 of a governor 225 which will be closed, if a train is proceeding in excess" of apredetermined speed, through Wires 226 and contacts V221 and 228 of an air reduction release relay 229 in the train line 230 through wire 23| to slowly operate air valve control 232 and' automatic brakeoperating valve 233,.wire 234 to battery 220. The

yellow or caution lamp 2|1 will remain lighted Y until the next transmittedmeans is passed and a new signal indication is given. vAs long asrelay |52 is locked'up andits contacts 2|8 and -2|!) are closed and mechanical governor 225, which is mechanically connected to the wheels orfother moving parts of the locomotive, is operated and its contacts 223 and 224 areclosed, the train is operating in excess of the previously determined speed. If the manualY brake valve -235is`fnt 'operated to reduce the pressureinthe train yline 239 to a point wherepressurerelease relay 229 will open, to thereby open its contacts 221 and 228, 'a service application of the brakes will be made by automatic brake operating `valve 233 in conjunction with 'slow-operating air Valve control 232. If manual' brake valve 235 isI operated,

`reducing the trainfspe-ed, governor 225v opensits contacts 223 and 224. If manual brake'valve 235 isV not operated, a service application of'brakes will be made by means of the automatic brakeoperating valve 233 in conjunctionwithy slowoperating'air valve control 232, reducing the train speed until governor 225 releases', thereby l'opening its contacts' 223 and 224.` No further reduction will be made during 'theperiod relay |52 is closed and the yellow or caution lamp is lighted. When the next' signal is received 'and relaysv 481,

93 and 99 operate, thelocking circuit on'relay |52 will'bev opened through their respectivev contheir non-operatedpositions forfthe'n'ext signal 7 .rectiier 96 tooperate .reiaylawith relays t81 arid-.itin their-noneoperatedposition, .then con- '.tacts v| landll |I1,and .I |.8 and ||9 .of relay 81 Awill 'he open; icontagcts :|20 and' |42 |,;and v|22-and U|23 ofrelayfl .will'be.closedycontacts 4|24-and |251of.relay 93` will be opencontactsflZB and |21, |28 and .|,29,:and,|30 andl'l3lofrrelay=93will be closed; contacts-|32and |33, |34 and-|35, |136 and |31,tand |38 and .|139 ofrelay ,-99` will" be closed; `contacts |40jand |4|, and |42 and-|43 of .relay .99 Will'be open. In this condition-battery energy is applied to relay |54 by battery |53 through wire '236,1contacts |36 and |31 of. relay 89, wire $231,':contacts |28 and |29 of relay'93, wire 238, contacts |28 and `|2| `of'r-elaylT, Wires'239 and `240to one winding of'relay |54. Relay |54 being aslow-release, relay, will bellockedin its operated Hposition after relays 81,193 "and 99 havesreturned to normal ornon-operated positions by means of battery |84applied to the second winding ofrelay |54through lwire |85, contacts |42 and |43 of re- 1ay'99, Wire |86, contacts-|30 and |3| of-relay'81, -Wires |88, |89 and 24|, second'windingiof relay |54, wire 242, contacts 243 and 2440i relay |54, wires |95'and-l96 returned'tobattery |84.v -Contacts 245 and 246 'of-relay |54 areclose'd, there- `by applying energyfrom battery 241to wire .248, contacts -245 and 246 of relay |54, wires 249 and 250 to Vred or'stop lamp 25|. Withrelay :|54 closed,litsfcontacts 252 and 253'are closed, thereby applying energy from' battery 254 through `wires-255 and 256, contacts 253and 2523o'f relay |54,wires 251and 259,contacts 259 an'd'260of mechanical governor 26| which will be closedif .the train is exceeding 'al-predetermined speed. I

Wire 262 to contacts'263 and 264 cf pressure re- Vlease relay V265 'through wire 266 to slow-operating air valve control 261,'whose operation vis set to a predetermined timeinterval, associates automatic brake-operating valve 268,'wire 269 to bat-V tery 254. Onreceiving a stopvsignal, if the train is'brought to a stop or a predetermined brake reduction is made by means of manual valve 235, therebyopening the contacts 259 and'260 of'govi ernor 26|, no brakeapplication Will be made by automatic brake-operating valve 268.

`Asrpreviously described, if the signal is not ereceived on--receiving means |55 .and a signal is Areceived-'on receiving element 56, relay |12 will close, and, being a slow-'release relay, will lock up through contacts |42 and |43 of `relay 99, |38 and |3| of relay'93, and |221and |23 of relay v81, wires |88, 210, second winding of relay |12, wire 21|, contact |18 and |19 of relay |12, Wire |96-to battery |84 and wire |85. When relay |12 closesfit closes its contacts 212 and 213 which apply energy from battery 214, wire 215 through contacts 212 and 213 of relay |12, wires 216 and 211 and lamp 218, thus indicating that it isnot functioning properly. When relay |12 is'in its operated position, contacts 219 and 280 are closed Yor operated, thereby applying energy from battery 254, through wire 255, contacts 21.9 and 289 o of relay |12, wires 28| and 258 through contacts 259and 260 of governor 26| to wire 262 to contacts 263 and 264 of pressure release relay 265 to wire 266 to slow-operate air valve control 261 and Aassociated `automatic brake-operating valve 268and-wire'269. The koperation of the manual or automatic brake application is thel same as that for red signal. A

If relay-99 fails to operate due to failure either of the transmitting means or'the receiving circuit and asignal is received on receiving element -.|55, closingor operating relay |64, energy will 4be lapplied torelay f|12,froin battery |69 through and |11. YIn this eevent, the alarm .and brake- Voperating circuit -will be set up,l in the same man- Anerasdescribed above. y i

-Our inventionfwhich is` employedin conjunction with thefstandard signallingfequipment at present in use, is intended to give signal indications to the .train crew of the signalsprovided by-said equipment; the invention being basedon ,a safety factorA involving the condition that-the clear signal produced -inr our. system depends A on the transmission of three low frequency signals; namely -in `the event any of those signals are not presentarestricted .(yellow) ora stop (red) indication will begiven. Or if all three low frequency signals larenot transmitted a warning signal Will be given indicating improper functioning ofthe equipment. The reception of. signals on .thereceiving means on .the vehicle .depends on two separate signals .being transmitted from the transmitting.means,-sothat inthe eventof failure of either one of thesesignals a restricted indication will be given on the vehicle, indicating that the equipment .isnot functioning properly. If the vehicle. passes the track signal and the next signal indications arenormal it willindicatethat the troubleis Yconfined to the signalor the .transmitting means just passed.

Our improved system involves'an `additional checking device of aA continuously ,transmitted signal which must be present Vatthe receiving means to provide proper operationof the receiving equipment. VThis checking device or signal is transmitted from aseparatesource with a separate transmitting element and receivedby a separate receiving element and receivngequipment and relay interlocked rwith the intelligence receiving unit, so that in the event this ,signal or all of the intelligence signals are notreceived an alarm is provided indicating to theengineer that a failure has occurred thereby-permitting him to take maximum precaution for the safety of his train.

In addition to the warning signal producedvon the vehicle, our invention involves .a further safety factor by providing brake applications it 4the vehicle operator fails to make proper brake applications in a predetermined .time interval after receiving a caution (yellow) or stop .(red) signal indication.

The reception of the signal indication from the signal passed on the track is locked up by the associated relay circuitsv in thereceiving means until the next signal of the railway signalling equipment is receivedv to re-set the receiving vequipment or means through the transmitting and associated receiving means.

In our improved system the Ysignal is transmitted by a, xed antenna and the intelligence is superimposed on that signal by relay control channels, thereby eliminating the necessity for semaphores7 and positioning antennas, thus permating operation with present'day type of railway signal systems.

The described exemplificati'on of our improved system is believed to be the best embodiment of the invention but certain modicationsl maybe possible Without departing from the spirit of our invention as defined in the appended claims.

What we claim is:

1. In a system of signal indication transmission and Vehicle control, the combination of the relay operated track circuits of standardrailway signalling equipment; atransmitting means comprising a relay containing control circuit ar fier; a xed directional transmitting means whose radiation is independent of the rails'of the track; and an independent checking circuit consisting of a continuously transmittingl highfrequency oscillator and a second fixed directionaltransmitting means whose radiation is independent of therails of the track and whose signal must be.

present in the receiving means on the vehicle to provide for its proper operation.

2. In a system of railroadl trackfsignal indication transmission and vehicle control, vreceiving means on the track vehiclecomprising apair of receiving elements which function inde-pendent of the rails of the track, one of saidreceiving elements having a circuit involving ahigh frequency ampliner, a demodulatcr for the output of said amplifier; a plurality of separate low frequency channels, each channel involving separate relays and separatelight indication means and sources of electrical energy; thelamp o-f one of said channels -becoming extinguishedV when the receiver becomes inoperative, while the other channels separately provide either la clear or green light indication-a yellow or caution light indication-or a stop or red light indication when signals are received by said last mentioned vreceiving element; a checking 'channel involving the other of said pair'of receivingv elements, a high frequency amplifier, a relay controlled circuit, a lamp .and electrical energy source wherebysaid lamp becomes lighted in the event'of failure of c said rst'mentioned receiving element torece'iv'e signals; in combination with the valve 'controlled 7 train air line, a pair of governors for separately controlling the train line valves, one of said governors and a train line valve being. operated with the yellowv o r caution light indication-channel whereby said governor and train line valve will operate and a service or light vehicle brake application made if the trainis `travelling in excess of a predetermined speed-- while the second governor which operates with the stop or red light indication channel and with a train line valve whereby the latter is actuated to provide an emergency or stop brake application.

3. A signal indio-ation transmission syste'in comprising, in combination with a standard railroad track block signal system provided with electrically operated relays; aj control circuit controlled by the track signal system relays; signal,

indication .transmitting means having a plurality of individual frequency channels and a pair of transmitting elements whose radiation is independentofthe rails of the track, one of said channels being controlled byv a track signal system relay ,and one of said channels being controlled by said control circuit; means whereby one or all o-f the signals from three .of said channels are transmitted by one of the transmitting elements; means whereby the independent checking signal from the fourth channel is continuously transmitted by the other of said transmitting elements; receiving means arranged on the l() track vehicle comprising'a pair of receiving elements which 'functionindependent of vthe rails'of the track,h a :plurality o-fV individual frequency channels, a plurality of, signal indication lamps, relay' Vcontrolled circuits intermediate the chan-k nels and said lamps; a pair ofnormallyV open cir? cuits involving means to actua'te valves in the air brake train line of 'the' vehicle onsaid 4 track adjacent said signal system and 'controlledb-y certain of' said last 'mentioned relay controlled Vcircuits whereby ya service brake application is obtained upon closure of one of said pairV of 'open circuits when one` of.' said channels provides a caution signal indication and an emergency 'brake application obtained upon closure of the otherof said pair of open'circuitsupo'n receipt by one of said vchannels of a stopsignal indication or failure'to receive the independently transmitted check signal in the event of failure by the vehicle operator to make brake applications'within predetermined time intervals.

`4.In'a signal indication system, operative in conjunction Vwith astandard railroad track electric signal system; receivingmeans arranged on the 'railroad vehicle `comprising va pair of receivingelements which Vfunction independent of the rails 'of thetrack;` a plurality of individual frequency channels.receivingsignals from one of said receiving elements aplurality of lamp controlling circuits connected to the outputs of said frequency channels, one of said last mentioned circuits. being operatedv in conjunction with the other of said pair of receiving elements; a vehicle air 'braketrain line provided with relay controlled pressure release valves; a pair of normally open circuits each, involving a governor and valve operating relays, said circuits. being "operatively intermediate certain ofj the 'frequency channels and Athejfpressure releasejvalve relays whereby service kbrake application is provided; and a nor-" mallycpen circuit'operative with the other of saidY pair of receiving [elements and having valve control relay," mechanism whereby fan emergency brake application is providedl after a pre'deter` mined time interval, bothof said brake applications being madein the `event of failure of manual brake oper-ation. f

5. In a signal indication and railroad vehicle control system, receiving means arranged on the railroad vehicle comprising a pair of signal receiving elements which function independent of airv brake train line pressure valvecontrollingcircuit which becomes effective through'said car-'f rier wave and upon reception of `signals byl said rst mentioned receiving ele'r'nent and failuierto receive a sign-al on the other` receiving 'element whereby the Iair brake train line pressure valve is vactuatedand theA vehicle brake application produced.

6. In a signal indication' and railroad vehicleP control system, the combination of an air brake" train line provided with a slow valvecontrol and a brake operating relay;f"receiving means arranged on the. railroad vehicle 'comprising a-p-air of signal receiving elements which function 'independent of the rails of `the' trac/Ka plurality 0f cieca-2er low frequency channels receiving'signalsfrom the receiving element, each channel comprising relay controlled lamp circuits to provide clear, caution or stop sign-als and an alarm lamp centaine ing circuit operatively associated withone of said pair of signal receiving elements whereby failure' of said last mentioned signal receiving element to receive a signal during reception of a signal by the other of said receiving elements said alarm lamp will become lighted and said slow valve; control and brake operating relaywill be actu-` ated to provide an emergency brake application ina predetermined time intervalunless the engineer has' responded to said alarm signal.

7. In a signal indication andrailroadvehicle control system, receiving vmeans arranged on the railroad vehicle consistingof a pairV of signal receiving` elements' which function independent of the rails`of the track; a plurality of'low frequency channels receiving signals from one of said receiving elements, said channels Vhaving relay contrlledx l'a-'mp circuits to provide clear, caution and`4 stop signals; the other of said pair of receiv' ing elements` constantly' receiving a high frequeney or carrier Waveland connected to a relay4 controlling. circuit; in combination with an air brake train line having. a' pressure controlling valve, -anda rela-y containing circuit operatively intermediate said last'mentio'ned relay controlling circuit and said pressure controllingjvalve wherebythe llatter is actua-ted t'o 'provide 'a' brake application intheevent a signal is received by said last mentioned'receivi'ng element-[and no signal is received. by. said firstv mentioned receiving element.

8'.l Asignaliindication and railroad vehicle controlfsysten comprising, in combination with' the, relay operated track circuits ofst-andard railway signallingcquipment; of transmitting means consisting` ofA a. relayV containing' controlV circuit' rto be controlledby relays of the' adj acenttrack 'cir-` cuits, a low frequency oscillator and. a plurality ofzsep'arate low` frequency conveying channels one, ofwhich is to be controlled by a track circuit relay,.a secondchannel'tb be controlled by arelay of said control circuit wliilv the. third is va continuously, closed or transmitting channel, a modulator and a high frequency source and a directional4v *transmitting means whose4 radiation K is independentfof the rails of'th'e track, a receive ing. means*v arranged on. the vehicle andV signal. receivin''gfelerneritsY which :function indepen'd-ienti of', the'- rails. of the "track, a' plurality of relayc'ontarni'ngv lou/frequency channels receiv-A ing' sign'alsfrornv olie of' saidisignal. receiving'e'le4` ments, all of saidj channels consistingY oirelay controlled lamp circuitsY forproviding a` clear or green signal upon'receptionfrom'* three of .thelow frequencychannels ofthe transmitting means, a' caution'ior" yellow signal upon reception of` the low' frequencyjsi'gnals from' two'of the'A low frej4 quency, channels of the transmitting means, while; a redjo'r stop. signal on the receiving meansl is; dependent' on the'receptionof a' signal from onen lowfrequency channelof saidtran'smitting means whereby in the event ofl failure in one ofI the channels of the transmitting means a restrictive indicationv in` the receiving means is lalways received.

9; In' a signal indication land railroad vehicle controlV system, transmitting means operated by a.v pair' of interlocked relay operated track cir-U cui-ts' of' a standard railway signalling equipment', said' transmitting means comprising a relay"con taining control circuit controlled by the relays ofv said adjacent pair of trackv circuits, ya low frequency oscillator witha-plurality of separatefrequencylconveying'channels each consisting of a band filter, one of the channels beingcontrolled by' a4 trackV circuit relay, a second channel being c'ontrolledby 'the relay of said controlv circuit,

while a; third constitutes a continuously transmitf ting; channel, a` modulator and high frequency oscillatorl connected to said modulator, amplifying means, av fixed'- directional transmitting clef ment 4whose `radiation is independentofthe rails of theI track associatedwith the'output of saidv modulator, a' high frequency'oscillator, amplify-4 ingnieans andv a, second fixed directional transf mitting element whose radiation is'independent of /therails vof the track which continuouslyv transmitsa signal; the' signals of' saidjcontinuously` transmitting channel and saidhigh' frequency oscillator provide a red or stop indication and effect an emergency brake application.

10. In afsi'gnal indication and railroad vehicle control system, signallreceiving means arranged on theA vehicleV comprisingv signal receiving velements; which function independentof the lrails of the track, high frequency amplifiersconnected t0' said elements, a demodulator andY amplifier, a plurality ofl low frequency channels operatedV by saidrlast mentioned-amplifier and'each consisting of relays and light signal providing circuits, a circuit checking local oscillatorfor feeding a continuous signal into the receivingy means, one of sa'idchannels controlling anormally closed lamp circuit, whereby failure in the receiving means will-be indicated-by the lamp of said normally ly receives a-hignfrequency or carrier waveandv is connected to a*l highfrequency amplifier, rectifying means and a relayV controlled circuit, and' a normally open circuit consisting'of/ a slow or time interval control element and said-automaticy brake linevalve, whereby the high frequency wave receivedf'byY the lastV mentioned receiving element andv failure of reception of a signal byY said first mentioned receivingjelement will close= said last mentioned normallyl open circuit and effect brake-application.

12. In-a signal indication'and railroad vehicle control-system, signal receiving means arranged on the vehicle comprising a pair of signal -re` ceivingelements which function independent of the railsoff the track, a continuous signal-prof viding oscillator, a high frequency amplifier; a demodul-ator, a lowfrequency amplier andafpl'u ralityofL channels all. associatedY with one of said receivingV elements; the signals received bycerfv tainofsaid channels being adapted to control 0 clear; caution and stop light providing circuits,

while the signal from the` aforementioned oscillator controls aA normally closed alarm signal ciraA relay connected to the other ofj said pair of LILBURN R. THOMAS. CHARLES A. CROUCH.

REFERENCES CITED The following references are of record in the le of this patent:

5 UNITED STATES PATENTS Number Name Date 1,816,628 Williams et al. July 28, 1931 1,882,027 Nicholson Oct. 11,v 1932 

